Yanornis

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Yanornis was an Early Cretaceous bird, thought to be closely related to the common ancestor of all modern birds. One species, Yanornis martini ^[1], has been described from fossils found in the Jiufotang Formation at Chaoyang, Western Liaoning province, PRC, and as of 2004 five specimens were known (Zhou et al., 2002). It was the size of a large pigeon, had a long skull with about 10 teeth in the upper and 20 teeth in the lower jaw, and was both able to fly and walk well. It ate fish (Zhou et al., 2004), and in the associated adaptations shows remarkable convergent evolution to the unrelated enantiornithine Longipteryx (Zhou & Zhang, 2001).

[edit] Taxonomy

In a 2006 study of early bird relationships, Clarke et al. found that Yanornis, Yixianornis, and Songlingornis formed a monophyletic group (since Songlingornis was the first of these birds to be described, the family containing this group is Songlingornithidae, within the order Yanornithiformes).

Yanornis gained notoriety when the front half of a fossil bird was combined with the tail of a Microraptor to make the paleontological forgery "Archaeoraptor". Upon discovering this, the bird half was described as Archaeovolans repatriatus, which was later found to be a junior synonym of Yanornis.

[edit] References

• Clarke, Julia A.; Zhou, Zhonghe & Zhang, Fucheng (2006): Insight into the evolution of avian flight from a new clade of Early Cretaceous ornithurines from China and the morphology of Yixianornis grabaui. Journal of Anatomy 208 (3):287-308. DOI:10.1111/j.1469-7580.2006.00534.x PDF fulltext Electronic Appendix

• Zhou, Zhonghe & Zhang, Fucheng (2001): Two new ornithurine birds from the Early Cretaceous of western Liaoning, China. Chinese Science Bulletin 46 (15): 1258-1264. PDF fulltext

• Zhou, Zhonghe; Clarke, Julia A. & Zhang, Fucheng (2002): Archaeoraptor's better half. Nature 420:285. DOI:10.1038/420285a (HTML abstract) Supplementary information

• Zhou, Zhonghe; Clarke, Julia A.; Zhang, Fucheng & Wings, O. (2004): Gastroliths in Yanornis: an indication of the earliest radical diet-switching and gizzard plasticity in the lineage leading to living birds?. Naturwissenschaften 91:571-574. PDF fulltext

[edit] Footnotes

1. ^ Yanornis, from the Ancient Chinese Yan dynasties, whose capital was at Chaoyang, and Ancient Greek ornis, "bird". martini, dedicated to avian paleontologist Larry D. Martin.